2D25

C-C-A-G-G-C-M5C-T-G-G; HELICAL FINE STRUCTURE, HYDRATION, AND COMPARISON WITH C-C-A-G-G-C-C-T-G-G

2D25 の概要

• エントリーDOI: 10.2210/pdb2d25/pdb
• 分子名称: DNA (5'-D(*CP*CP*AP*GP*GP*CP*(5CM)P*TP*GP*G)-3'), MAGNESIUM ION (3 entities in total)
• 機能のキーワード: b-dna, double helix, modified, dna
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 6144.35

構造登録者

Heinemann, U.,Hahn, M. (登録日: 1991-04-23, 公開日: 1991-04-23, 最終更新日: 2024-02-14)

主引用文献

Heinemann, U.,Hahn, M.
C-C-A-G-G-C-m5C-T-G-G. Helical fine structure, hydration, and comparison with C-C-A-G-G-C-C-T-G-G.
J.Biol.Chem., 267:7332-7341, 1992

PubMed Abstract: The self-complementary DNA duplex C-C-A-G-G-C-m5C-T-G-G has been refined against 1.75-A x-ray diffraction data to an R value of 17.4%. In the crystal of space group P6, 10-base pair DNA fragments with characteristic sequence-related fine structure stack end to end to form long antiparallel B-type double helices. As shown by a structure analysis at lower resolution (Heinemann, U., and Alings, C. (1991) EMBO J. 10, 35-43), the overall geometry of C-C-A-G-G-C-m5C-T-G-G is similar to that of the unmethylated analog C-C-A-G-G-C-C-T-G-G despite a different crystal environment. The present high resolution structure analysis permits a detailed comparison of the two duplexes and their hydration spheres. Helical parameters are significantly correlated between both molecules, with the exception of the base pair propeller. Sugar pucker and backbone torsion angles alpha, gamma, delta, and chi show similar mean values, but their individual values deviate significantly between duplexes. In contrast, torsion angles beta, epsilon, and zeta change along the strands of both duplexes in much the same way. The effect of single-site methylation on DNA conformation appears to be small and limited to the base pairs directly involved. Methylation tends to push base pairs toward the minor groove of the helix. A regular minor groove hydration pattern involves dual hydrogen bonding of water molecules to O-4' and base atoms of C-C-A-G-G-C-m5C-T-G-G.

PubMed: 1559976

実験手法

X-RAY DIFFRACTION (1.75 Å)